The effect of metabolic inhibitors on the development of respiration in anaerobically grown yeast.

1. Iodoacetate and fluoride did not prevent the development of respiration in aerobically grown yeast. 2. The effect of dinitrophenol suggested that phosphorylation developed simultaneously with respiration in anaerobically grown yeast, but the effect of oligomycin suggested that the phosphorylation and oxidation were not tightly coupled. 3. Inhibitors of electron transport showed that both the respiratory peak and the subsequent respiration were cyanide-sensitive, but the peak respiration was insensitive to antimycin. 4. Of the inhibitors of protein or RNA synthesis tested, only p-fluorophenylalanine inhibited the development of respiration. The results are not consistent with a new synthesis of mitochondria. 5. 2-Phenylethanol inhibited the development of respiration in anaerobically grown yeast and also yeast growth. Other inhibitors of DNA synthesis had no effect on the development of respiration. 6. The relevance of the results to mitochondrial morphogenesis is discussed.